Influence of Biotope and Biotic Factors on Cyanobacteria Abundance, Genotype and Toxin Production

2021 ◽  
Author(s):  
Maria Iasmina Moza ◽  
Carmen Postolache
Keyword(s):  
Chemical Elements ◽  
Toxin Production ◽  
Water Bodies ◽  
Ecological Groups ◽  
Biotic Factors ◽  
Nitrogen And Phosphorus ◽  
Modern Methods ◽  
Environmental Genetics

Environmental genetics-related modern methods are shown as important indicators of various cyanotoxins syntheses, and their knowledge and use are critically analyzed. Microcystins and other cyanotoxins loads and syntheses are related to different drivers, like various chemical elements and compounds (especially nutrients, such as nitrogen and phosphorus, and their ratio), then to the light, conductivity, temperature, and other climatical and hydrological factors, to which spatial and geographical features (such as the surface of the water bodies) have to be added. The biotic relationships include different specific and supraspecific, uni- and bilateral links between the cyanobacteria, and subsequently their synthesized toxins, and protozoans (or protoctists), chromists, macrophytes, different systematical and ecological groups of zooplankton, and others. The importance of, but also the gaps in, the knowledge and the scarcity of studies involving ectocrines mediated interactions between different groups of algae and plants are highlighted. The paper ends with an interesting classification of lakes' trophicity, illustrated with conceptual diagrams, based on possible scenarios of cyanobacteria behavior.

Phytoplankton Production and Decomposition Characteristics in Water Bodies Differing in the Degree of Their Contamination by Inorganic Compounds of Nitrogen and Phosphorus

2019 ◽  
Vol 55 (3) ◽  
pp. 29-43 ◽  
Author(s):  
P. D. Klochenko ◽  
T. F. Shevchenko ◽  
I. N. Nezbrytskaya ◽  
Ye. P. Belous ◽  
Z. N. Gorbunova ◽  
...  
Keyword(s):  
Inorganic Compounds ◽  
Water Bodies ◽  
Phytoplankton Production ◽  
Nitrogen And Phosphorus

scholarly journals Evolution of organismal stoichiometry in a long-term experiment with Escherichia coli

2017 ◽  
Vol 4 (7) ◽  
pp. 170497 ◽  
Author(s):  
Caroline B. Turner ◽  
Brian D. Wade ◽  
Justin R. Meyer ◽  
Brooke A. Sommerfeld ◽  
Richard E. Lenski
Keyword(s):  
Escherichia Coli ◽  
Phosphorus Content ◽  
Chemical Elements ◽  
Relative Proportion ◽  
Total Carbon ◽  
Nitrogen And Phosphorus ◽  
Serial Transfer ◽  
Evolutionary Changes ◽  
Long Time ◽  
Long Term Experiment

Organismal stoichiometry refers to the relative proportion of chemical elements in the biomass of organisms, and it can have important effects on ecological interactions from population to ecosystem scales. Although stoichiometry has been studied extensively from an ecological perspective, much less is known about the rates and directions of evolutionary changes in elemental composition. We measured carbon, nitrogen and phosphorus content of 12 Escherichia coli populations that evolved under controlled carbon-limited, serial-transfer conditions for 50 000 generations. The bacteria evolved higher relative nitrogen and phosphorus content, consistent with selection for increased use of the more abundant elements. Total carbon assimilated also increased, indicating more efficient use of the limiting element. We also measured stoichiometry in one population repeatedly through time. Stoichiometry changed more rapidly in early generations than later on, similar to the trajectory seen for competitive fitness. Altogether, our study shows that stoichiometry evolved over long time periods, and that it did so in a predictable direction, given the carbon-limited environment.

Stable isotopes as a tool for determining transformation and fate of sulphur in AMD affected water bodies in Meghalaya

2021 ◽  
Author(s):  
Vivek Kumar ◽  
Dibyendu Paul ◽  
Sudhir Kumar
Keyword(s):  
Stable Isotopes ◽  
Coal Mining ◽  
Environmental Fate ◽  
Mine Drainage ◽  
Chemical Elements ◽  
Aquatic Systems ◽  
Water Bodies ◽  
Hydrochemical Parameters ◽  
Dominant Form ◽  
Mining Areas

<p>Meghalaya, also known as ‘abode of clouds’, is a state located in north-eastern part of India, blessed with abundance of water resources. In the last few decades, extensive coal mining in different parts of Meghalaya has caused detrimental changes in the environment, particularly the aquatic systems. Acid and metal loaded effluents (also known as acid mine drainage or AMD), resulting from the exposure of sulphide mineralization to oxidizing conditions from abandoned or active mining areas, are the principal environmental problems today. Sulphate (SO<sub>4</sub><sup>2-</sup>) is a major contaminant and attracts widespread attention as the dominant form of sulphur in coal mining affected aquatic systems. The increased presence of SO<sub>4</sub><sup>2- </sup>in ecosystems affected by mining activities has immense negative environmental and human health effects. Low pH and high heavy metal concentrations have been reported from streams flowing in and around the coal mining area in Meghalaya rendering the water quality to be very poor  and unfit for use as potable water.</p><p>Stable isotopes have emerged as a promising environmental tracer to understand different environmental functions and processes. Valuable information on the sources and processes can be obtained from the stable isotope ratios of chemical elements in environmental samples as the sources and processes influence history of the samples. Stable isotopes analysis combined with hydrochemical analysis enhances our understanding of transformation and environmental fate of different compounds in water bodies and can provide precise information about factors responsible for controlling water chemistry of different water bodies.</p><p>Stable isotopes of sulphur and oxygen combined with hydrochemical parameters were used as a tool for determining origin, transformation and fate of sulphur in AMD affected water bodies in Meghalaya.The study was conducted on two rivers affected by AMD, viz. Myntdu River and Lunar-Lukha River, flowing in the Jaintia Hills region of Meghalaya. The water samples collected are analysed for hydrochemical parameters and stable sulphur and oxygen isotopes (δ<sup>34</sup>S and δ<sup>18</sup>O in aqueous SO<sub>4</sub><sup>2-</sup>). The stable isotopes of sulphur and oxygen were also analysed in the coal samples from the nearby mining areas. The result provided an insight into the transformational processes of sulphur in these two AMD affected rivers and the environmental fate of sulphur.</p>

Nutrients Pollution in Water Bodies

2017 ◽  
pp. 21-42
Author(s):  
Ángeles Val del Río ◽  
Paula Carrera Fernández ◽  
José Luis Campos Gómez ◽  
Anuska Mosquera-Corral
Keyword(s):  
Climate Change ◽  
United States ◽  
Human Health ◽  
The United States ◽  
Water Bodies ◽  
Nitrogen And Phosphorus ◽  
International Conventions ◽  
Laws And Regulations

The pollution of water bodies by an excess of nutrients (N and P) is a worldwide problem with effects on the human health, ecosystems status, climate change, etc. To face with this important issue different regulations were promulgated by the countries, sometimes based on the results from international conventions and programmes. In this chapter, a review of the laws and regulations that affect the discharge of nitrogen and phosphorus is addressed, focused in the case of Europe and the United States. Finally, a brief explanation about international initiatives was performed to understand the global framework concerning nutrients pollution.

scholarly journals XIII. Revision of the atomic weight of gold

1889 ◽  
Vol 180 ◽  
pp. 395-441 ◽  
Keyword(s):  
Royal Society ◽  
Original Work ◽  
Atomic Weight ◽  
The Other ◽  
Organic Substances ◽  
Modern Methods ◽  
Gold Compounds ◽  
Chemical Section

Until lately gold ranked among the elementary substances of which the general properties had been well ascertained, but in regard to the atomic weights of which our knowledge was least satisfactory. That this constant should be determined as accurately as possible for gold was desirable in view of its bearing on the precise place assigned the metal in the “periodic” classification of the elements based on the ideas of Newlands, Odling, Mendelejeff, and L. Meyer. Furthermore, an exact know­ ledge of the atomic weight of gold might be conveniently applied in the determination of the atomic weights of some of the other elements. A practical laboratory reason for desiring to possess a trustworthy value for this constant was also presented by the facility with which gold compounds of many organic substances may be prepared, and the ease with which their composition may be ascertained by simple ignition in the air and weighing of the residual gold, the results leading to a knowledge of molecular composition when the atomic value of the weight of the metal obtained is assumed to be known. For the last three years and a half I have been occupied, during a large part of such time as has been available for original work, in devising and carrying out experiments aiming at the redetermination of the constant in question. The difficulties met with have been greater than were at first looked for, and have led to much time and labour being consumed in attempts to overcome them. About two years ago, when this work was already well under way but still in progress, there appeared the results of experiments aiming at the same end, by Kruss in Germany and by Thorpe and Laurie in England—experiments made with the care and accu­racy of modern methods, and apparently deserving of much confidence. My own work, however, was continued, as we cannot have too many careful independent determinations of atomic weights by different workers, and as I had used to a con­siderable extent other procesess than those on which the newly published determina­tions were based, while the chemists named had employed, in the main, one and the same method. A preliminary notice of my work was read in the Chemical Section of the British Association at the Manchester meeting of 1887. The details of my experiments and the results which I have reached are now laid before the Royal Society.

scholarly journals Ecological engineering of small urban water bodies

2020 ◽  
Vol 157 ◽  
pp. 02026
Author(s):  
Antonina Suzdaleva ◽  
Anna Hirsch ◽  
Maria Kuchkina
Keyword(s):  
Ecological Engineering ◽  
Interdisciplinary Approach ◽  
Water Bodies ◽  
Urban Water ◽  
Prognostic Assessment ◽  
Technical Maintenance ◽  
Technical Systems ◽  
Positive Functions

The ecological and sanitary epidemiological condition of small urban water bodies is an important factor in ensuring safety in urbanized areas of the technosphere. All modern small urban water bodies are naturaltechnical systems that can be uncontrollable or controllable. In managed natural-technical systems, favorable environmental conditions are formed as a result of the operation of special engineering devices and systems called ecological regulators. Their creation and ensuring sustainable existence are the main goal of ecological engineering of small urban water bodiesThe choice of a strategy for the environmental engineering of water bodies should be determined on the basis of a prognostic assessment of the possibility of improving or maintaining its positive functions: videoecological, recreational, biotopical potential, and also cultural, historical or religious significance. In addition, it is necessary to take into account public opinion, which can be changed by disseminating positive information about the goals of the proposed activity (active ecological image-making). The issue of organizing long-term technical maintenance of ecological regulators and monitoring of natural-technical systems of water bodies is being considered. The paper provides a classification of small urban water bodies and a generalized scheme of their ecological engineering. The necessity of an interdisciplinary approach to decision making and the development of syncretic thinking in this area is substantiated.

scholarly journals Chemical Element Concentrations of Cycad Leaves: Do We Know Enough?

Horticulturae ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 85 ◽  
Author(s):  
Benjamin E. Deloso ◽  
Murukesan V. Krishnapillai ◽  
Ulysses F. Ferreras ◽  
Anders J. Lindström ◽  
Michael Calonje ◽  
...  
Keyword(s):  
Root Zone ◽  
Chemical Elements ◽  
Incident Light ◽  
Leaf Age ◽  
Influential Factors ◽  
Nutrient Concentrations ◽  
Future Research ◽  
Nitrogen And Phosphorus ◽  
Element Concentrations

The literature containing which chemical elements are found in cycad leaves was reviewed to determine the range in values of concentrations reported for essential and beneficial elements. We found 46 of the 358 described cycad species had at least one element reported to date. The only genus that was missing from the data was Microcycas. Many of the species reports contained concentrations of one to several macronutrients and no other elements. The cycad leaves contained greater nitrogen and phosphorus concentrations than the reported means for plants throughout the world. Magnesium was identified as the macronutrient that has been least studied. Only 14 of the species were represented by data from in situ locations, with most of the data obtained from managed plants in botanic gardens. Leaf element concentrations were influenced by biotic factors such as plant size, leaf age, and leaflet position on the rachis. Leaf element concentrations were influenced by environmental factors such as incident light and soil nutrient concentrations within the root zone. These influential factors were missing from many of the reports, rendering the results ambiguous and comparisons among studies difficult. Future research should include the addition of more taxa, more in situ locations, the influence of season, and the influence of herbivory to more fully understand leaf nutrition for cycads.

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